Do not discard WSAECONNRESET error code from UDP under Windows

When a datagram is sent to a closed host/port combination, the host will
likely send back an ICMP error message. In the regular socket API, there
isn't a good way of actually receiving this error, so some Windows kernels
wired that message back up to the call to WSARecvFrom() as a synthetic
datagram. Reading this datagram results in a WSAECONNRESET error code,
which should reported to the user as a refused connection attempt.

To make the errors a bit more informative, the native error strings for
WSAECONNRESET and WSAENETRESET were also added.

Task-number: QTBUG-49301
Change-Id: If659be54ba1b39965b5f481f0c0cb9eeea0a06d2
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Markus Goetz (Woboq GmbH) <markus@woboq.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/network/socket/qnativesocketengine.cpp b/src/network/socket/qnativesocketengine.cpp
index 386e0e2cc7..dfece60036 100644
--- a/src/network/socket/qnativesocketengine.cpp
+++ b/src/network/socket/qnativesocketengine.cpp
@@ -275,6 +275,12 @@ void QNativeSocketEnginePrivate::setError(QAbstractSocket::SocketError error, Er
     case TemporaryErrorString:
         socketErrorString = QNativeSocketEngine::tr("Temporary error");
         break;
+    case NetworkDroppedConnectionErrorString:
+        socketErrorString = QNativeSocketEngine::tr("Network dropped connection on reset");
+        break;
+    case ConnectionResetErrorString:
+        socketErrorString = QNativeSocketEngine::tr("Connection reset by peer");
+        break;
     case UnknownSocketErrorString:
         socketErrorString = QNativeSocketEngine::tr("Unknown error");
         break;